Explanation:

The given clinical scenario of blurred vision and given fundoscopy finding of pizza pie appearance in a retropositive patient is suggestive of CMV
Cytomegalovirus (CMV) is a widespread herpesvirus which is a double stranded DNA virus and can cause severe illness in immunocompromised individuals.
The virus has a tendency to cause massive enlargement of infected cells with distinctive intranuclear inclusion bodies, leading to the term “cytomegalic inclusion disease.”
In normal hosts, CMV is spread through close contact with infected bodily fluids, with a 4–8 week incubation.
The infection may cause a mononucleosis-like illness with systemic symptoms or may remain subclinical.
CMV establishes lifelong latency and can be shed from the pharynx and in urine for months to years. It may cause prolonged kidney infection without major harm and often involves the salivary glands.
Cell-mediated immunity is suppressed during primary infection, contributing to viral persistence and delayed immune recovery.
In immunosuppressed individuals, CMV infections are more severe and may lead to pneumonia, hepatitis, colitis, or disseminated disease. These individuals are at risk for reactivation of latent virus, and CMV can cause significant morbidity and mortality.
Bone marrow and solid organ transplant recipients are particularly vulnerable, and CMV is a common cause of virus-associated leukopenia and rejection-related complications.
In immunocompromised individuals, cytomegalovirus (CMV) infection which is termed “CMV syndrome” typically begins with nonspecific symptoms such as fatigue, fever, general malaise, appetite loss, night sweats, and joint or muscle aches.
Respiratory symptoms such as rapid breathing, low oxygen levels, and a dry cough suggest pulmonary disease.
CMV can also affect the gastrointestinal tract, particularly in immunocompromised patients, where the involvement can range from localized to widespread. Among organ transplant recipients, colitis is the most frequently encountered manifestation. Additionally, CMV may cause ulcerations in the esophagus, stomach, small bowel, or colon, which can potentially lead to bleeding or perforation.
CMV retinitis commonly presents with reduced vision due to macular involvement or floaters from vitritis, initially affecting one eye but progressing to both in about half of untreated cases.
Retinitis appears as peripheral dense white retinal infiltrates with flame-shaped hemorrhages leading to a pizza pie appearance, extending along vascular arcades, with granular, non-central lesions being less aggressive (indolent) and central lesions being more fulminant and visually impairing.
Congenital CMV infection can lead to developmental delays, or mental retardation. Infection can occur transplacentally, during delivery, or postnatally via breast milk.
Infants infected in utero during primary maternal infection are at higher risk of symptomatic disease. While most neonatal infections are subclinical, some are chronic with persistent viral shedding.
Intrauterine CMV can lead to serious complications like microcephaly, hepatosplenomegaly, retinitis, periventricular calcification, and sensorineural deafness.
CMV causes a mild, mononucleosis-like illness in immunocompetent children and adults.
Diagnosis of CMV involves detection of viral DNA by PCR, viral culture in fibroblasts, or serology for IgM and IgG. However, serology is not reliable in immunocompromised patients.
Treatment options include ganciclovir (effective against life-threatening infections and progressive hearing loss), foscarnet, and cidofovir for resistant strains.

Explanation of other options:

Syphilis (Option B): Ocular syphilis can manifest as anterior uveitis, which may be granulomatous or non-granulomatous, and is bilateral in half of the cases. Chorioretinitis, often multifocal and bilateral, may be accompanied by vitritis and exudative retinal detachment. Other features include optic neuritis, neuroretinitis, and additional inflammatory or neuro-ophthalmic findings such as Argyll Robertson pupils.

Varicella-zoster virus (Option C): Progressive retinal necrosis (PRN), also referred to as progressive or posterior outer retinal necrosis (PORN), usually caused by varicella-zoster virus presents with rapidly worsening vision, affecting one or both eyes. It is marked by minimal anterior uveitis and vitritis. The condition primarily affects individuals with AIDS or other immunosuppressed states and often results in a poor visual prognosis, with over half of affected eyes losing light perception.

Toxoplasma gondii (Option D): Ocular toxoplasmosis often presents as posterior uveitis, with symptoms including floaters, blurred vision, and photophobia. It is commonly characterized by a solitary focus of fluffy white retinitis adjacent to a pigmented chorioretinal scar, with associated vitritis giving a “headlight in the fog” appearance as shown below.

QBank: NEET PG